Other genetic sideroblastic anaemias which present similarly and may need exclusion include Pearson syndrome (caused by mtDNA deletions) with sideroblastic anaemia, exocrine pancreatic failure and pancytopaenia [25]; and YARS2 and PUS1 deficiency which cause myopathy, lactic acidosis and sideroblastic anaemia (MLASA) syndrome [26–28]. The gene discussed is PUS1; the disease is Pearson syndrome.